Tuesday 11 February 2014 04.31 EST
First published on Tuesday 11 February 2014 04.31 EST

Smoking in cars carrying children will be banned in England after MPs backed the idea in a free vote, Downing Street sources have confirmed.

The government will try to draw up legislation before the next election after the House of Commons supported the plan, first put forward by Labour.

MPs voted overwhelmingly in favour by 269 votes despite the misgivings of some cabinet members, including Nick Clegg, over whether it would be too difficult to police.

Under the proposal the government now has powers to introduce a new offence of exposing children to smoke in vehicles, with breaches of the law likely to incur a small fine. The Welsh government will make a separate decision about what happens in Wales.

Ministers gave no timetable about when they would implement the plan or how they would iron out difficulties, such as whether it would be criminal for a 17-year-old to smoke in a car alone.

However, David Cameron, who missed the vote, gave his personal backing to the idea on Monday, despite the government saying last week there was no need for the legislation.

"While he understands the concerns that some have expressed, his view is that the time for this kind of approach has come," the prime minister's spokesman said.

The shadow public health minister, Luciana Berger, who campaigned on the issue, said it was a "great victory for child health which will benefit hundreds of thousands of young people".

She added: "It is a matter of child protection, not adult choice. The will of parliament has been clearly expressed today and this must be respected. Ministers now have a duty to bring forward regulations so that we can make this measure a reality and put protections for children in place as soon as possible."

The ban divided Conservative backbenchers, with several canvassing the views of constituents on social media.

Others, such as Philip Davies and Charles Walker, spoke strongly against the ban on the grounds of civil liberties and fears it would be unenforceable. However, 376 MPs voted in favour and 107 against – with support from politicians from all parties.

The issue arose after Labour proposed an amendment to the children and families bill allowing ministers to bring in regulations to make it an offence for a driver to "fail to prevent smoking in the vehicle when a child or children are present".

The government opposed the amendment, with the Department of Health saying it did not think legislation was the most effective way of stopping adults smoking in front of children in cars. This was reiterated in the House of Lords by Lord Howe, a health minister, who said it would be complex to police and the government preferred "behaviour change".

However, a coalition of Labour, Lib Dem and cross-bench peers defeated the government. The government said it had responded to the wishes of the Lords by bringing forward its own "workable" amendment, giving MPs the chance to express their opinion on the matter.

Jane Ellison, a Tory health minister, said ministers would "take our steer on the principle of the issue then having heard the views of both houses" but did not give a firm timetable.

"In the event that legislation is to be brought in to stop smoking in cars carrying children, we should not measure success by the number of enforcement actions," she said. "We should measure success by the reduction in exposure to second-hand smoke. The government will listen very carefully to what parliament has to say on the important principle as to whether the government should have the power to legislate to prevent smoking in cars when children are present.

"We will then consider what needs to happen next which is why, if MPs will forgive me, I am not able to talk in great detail on some of the points you have asked me about because that is the next stage once we have heard the will of parliament expressed.

"However, whatever happens I have asked Public Health England to continue their work on behaviour change in this area, including through social marketing campaigns."

Before the vote, the cabinet was understood to be split on the issue, with Clegg saying he thought it would be too difficult to police. Other sceptics are thought to include Vince Cable, the business secretary; Chris Grayling, the justice secretary; and Eric Pickles, the communities secretary.

Labour has argued Britain should follow the example set by Australia, Canada and some US states, where smoking in cars with children is outlawed. Smoking in workplaces and enclosed public spaces has been banned since 2007.